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Comment by nubinetwork | Hacker News Reader

You could always do what race cars do, put an electric motor on the turbo so when you go back on the throttle, you get instant boost.

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Porsche is doing that on a road car now. It can also act as a generator to limit maximum boost instead of opening a wastegate.

https://www.motortrend.com/news/2025-porsche-911-gts-t-hybri...

Audi has been shipping electric compressor for 5 years now. They are prone to failures and they are on second revision now.

https://en.wikipedia.org/wiki/List_of_Volkswagen_Group_diese...

That's a different design; Audi uses a separate electric supercharger to fill in boost while waiting for its conventional turbochargers to spool up. Porsche is using a motor/generator built in to a turbocharger to spool it faster, and to recover energy at maximum boost.

F1 is getting rid of that system (MGU-H) for 2026 because it was costing the teams too much and it never seemed relevant to passenger vehicles.

When a tech path costs too much for F1, that's a good sign you won't be seeing it in a GM product any time soon.

OP system is just using a computer to get on the gas a little faster when the driver hits the pedal quickly.

Whatever F1 does or doesn't do has had extremely little relevance for passenger vehicles for at least the past 30 years.

I was thinking of that when I wrote the comment! I've heard of electric turbochargers, but I'm not sure how good they are under real-life conditions. Directly using heat energy from the exhaust (as opposed to introducing electric conversion losses) seems wiser to me. Part of me has always liked making use of what would otherwise be wasted to entropy.

In theory (though not a mechanic, just have an interest in this), the best middle-ground would be to retain the same design but add a motor to the turbocharger shaft which would mainly be reserved for spool ups -- is that what they're doing?

What you've described is exactly how the F1 MGU-H works (as I posted below). F1 is getting rid of it next year because it costs too much for an F1 team which should tell you a little bit about the complexity involved.

GM is doing nothing of the sort, it's just an ECU map. Guessing here, but if driver presses on the gas quickly (throttle accel > some set value), juice the engine map to create extra exhaust pressure to spool up the turbo impeller. It's all software.

You can use antilag as well to achieve the same effect without electric turbochargers

Bad for emissions though so it'd never be OEM.

Edit: Also bad for the valvetrain. 4T engines aren't really meant to be run as 2T..

Isn't anti-lag (the type that invokes combustion in the exhaust, anyway) terrible for turbochargers, long-term?

It's bad for everything but it's awesome

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